The conservative approach to radiation protection regards genetic effects as what type of phenomenon?

• A. Threshold
• B. Non-threshold
• C. Linear
• D. Non-linear

Answer: (B)

Genetic effects are treated as non-threshold in a conservative approach because there is no assumed safe dose for heritable mutations. Even very small amounts of ionizing radiation can cause DNA changes in germ cells that could be passed to offspring, so risk is considered to exist at all exposure levels and increases with dose. A threshold would imply a zero-risk zone below some dose, which this protective stance rejects. While dose–response can be linear at low doses under the LNT framework, the key idea here is that there is no safe dose, i.e., non-threshold.